DIP problem with time confirmations containing different UOMs

Hi,

I have the following situation:

Service oder with the following time confirmation:
1. cost type = S11000 and time = 10 H
2. cost type = S11000 and time = 277 MIN

In DP90 it presents me now two lines.
1. material 1234, qty = 10 H
2. material 1234, qty = 277 MIN

In the credit memo I have:
1. material 1234, qty = 10 H
2. material 1234, qty = 4,62 H

Based on my analysis, the confirmation for the same cost type is not summarized in DP90 due to the different UOM of the confirmation. Summarization is turned on for this cost type (so it works when I provide confirmations with H only for example).

So my question is, how can I summarize in DP90 process same cost types which leads to same material with same sales UOM?

THANK YOU!

Florian